Standard Method of Test for
Resistance of Concrete to Chloride Ion Penetration AASHTO Designation: T 259-02
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1.
SCOPE
1.1.
This method covers the determination of the resistance of concrete specimens to the penetration of chloride ion. It is intended for use in determining the effects of variations in the properties of concrete on the resistance of the concrete to chloride ion penetration. Variations in the concrete may include, but are not limited to, changes in the cement type and content, water-cement ratio, aggregate type and proportions, admixtures, treatments, curing, and consolidation. This test method is not intended to provide a quantitative measure of the length of service that may be expected from a specific type of concrete.
1.2.
The values stated in SI units are to be regarded as the preferred standard.
2.
TEST SPECIMENS
2.1.
The specimens for use in this test shall be slabs made and cured in accordance with the applicable requirements of T 126, “Making and Curing Concrete Test Specimens in the Laboratory.” Note l-This method contemplates the use of a minimum of four specimens for each evaluation with each slab not less than 75 mm (3 in.) thick and a minimum surface area of 17,500 mm2 (28 square inches).
2.2.
For this test the specimens shall be removed from moist curing at 14 days of age unless earlier removal is recommended by the manufacturer of a special concrete. The specimens shall then be stored until 28 days of age in a drying room of the type specified by T 160, Length Change of Hardened Hydraulic Cement Mortar and Concrete.
2.3.
When the test method is used to evaluate concrete treatments, the slabs shall be fabricated from concrete having a cement factor of 390 kg/m3 (658 Ib/yd3), a water-cement ratio mass of 0.5, and an air content of 6 f 1percent. The concrete treatment shall be applied at 21 days of age and in accordance with the manufacturer’s recommendations for field usage. Note 2-If field application of a sealer by spraying is recommended, the sealer should be applied to the specimens by spraying rather than brushing.
2.4.
When a special overlay material is to be evaluated, the concrete slab shall be cast 50 mm (2 in.) thick using the mix design specified under Section 2.3 and then the special overlay material shall be placed 25 mm (1 in.) thick, unless specified otherwise, according to the manufacturer’s recommendations.
Ts-3~ Copyright American Association of State Highway and Transportation Officials Provided by IHS under license with AASHTO No reproduction or networking permitted without license from IHS
T 259-1 Not for Resale
AASHTO
3.
PROCEDURE
3.1.
Immediately after the specified drying period stipulated in Section 2.2 (i.e., 29th day of specimen age), 3.2 1.6 mm (0.125 i 0.062 in.) of the slab surface shall be abraded using grinding or sandblasting techniques if the concrete or treatment are to be subjected to the wearing effect of vehicular traffic. No water shall be used in the abrading process. If the concrete or treatment is to be used on surfaces not subject to wear from vehicular traffic then the abrading step shall be omitted.
3.2.
Place approximately 19 mm (0.75 in.) high by 13 mm (0.5 in.) wide dams around the top edge of all slabs except one, which will then become the control slab. In lieu of this, a dam meeting these dimension requirements may be cast as an integral part of the slab. However, such previously cast dams shall not interfere with the abrasion of the surface as specified under Section 3.1.
3.3.
All slabs shall then be returned to the drying room as specified under Section 2.2 for an additional 13 days (i.e., until 42 days of age). Note &The degree of saturation of the specimens at the time of ponding will affect chloride ingress. In general, water saturated concrete will absorb significantly less chloride during the 90 days of ponding than a drier but similar material. Thus, for proper definition of chloride ingress by this method, the requirements in Sections 2.2 and 3.1 through 3.3 (for a total of 28 days of air drying prior to ponding) must be followed.
3.4.
The slabs with dams shall be subjected to continuous ponding with three-percent sodium chloride solution to a depth of approximately 13 mm (0.5 in.) for 90 days. Glass plates shall be placed over the ponded solutions to retard evaporation of the solution. Placement of the glass plates shall not be done in such a manner that the surface of the slab is sealed from the surrounding atmosphere. Additional solution shall be added if necessary to maintain the 13 mm (0.5 in.) depth. All slabs shall then be returned to the drying room as specified under Section 2.2.
3.5.
After 90 days of exposure the solution shall be removed from the slabs. The slabs shall be allowed to dry and then the surfaces shall be wire brushed until all salt crystal buildup is completely removed.
3.6.
Samples for chloride ion analysis shall then be taken from all slabs in accordance with the procedure described in T 260. These samples shall be obtained from each slab at each of the following depths unless otherwise directed by the specifying agency: rn 1.6 mm (0.0625 in.) to 13 mm (0.5 in.), and rn 13 mm (0.5 in.) to 25 mm (1.0 in.). The chloride content of each sample shall be determined in accordance with the instructions in T 260. Note &Many starter bits for use inside hollow rotary hammer pulverizing bits are significantly longer than the pulverizing bit. This results in a sampling depth which is greater in the center of the “core hole” than at the edges. To minimize this effect, the chuck end of the starter bit should be cut off such that its overall length does not exceed that of the outside bit by more than 1.6 mm (‘/i6 in.) (i.e., such that the variation in sampling depth is not greater than 1.6 mm (‘/I6 in.)). When it is desired to remove only 1.6 mm (‘/,a in.) of material from the surface of a test specimen or a bridge deck, it may be more convenient to complete that operation by use of a grinder. The sample can then be taken with the rotary hammer without fear of contamination from the salt on the surface of the item being sampled.
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TS-3C Copyright American Association of State Highway and Transportation Officials Provided by IHS under license with AASHTO No reproduction or networking permitted without license from IHS
T 259-2 Not for Resale
AASHTO
CALCULATIONS
4.1.
The baseline chloride ion content for the test specimens shall be determined as the average chloride ion content of samples obtained from the 1.6-mm (0.0625 in.) to 13-mm (0.5-in.) and 13mm (0.5-in.) to 25-mm (1-in.) depths within the slab that was not ponded with three-percent sodium chloride solution.
4.2.
The absorbed chloride ion content of each sample from the ponded slabs shall be determined as the difference between the total chloride ion content of that sample and the baseline value calculated in Section 4.1.If the result is less than zero, the result shall be reported as zero. The average chloride ion absorbed at each sampling depth shall be calculated.
5.
REPORT
5.1.
Reporting shall include (1) each total chloride ion value determined in Section 3.6, (2) the average and maximum baseline chloride ion (Section 4.i),(3) each calculated absorbed chloride ion value determined in Section 4.2,(4)the average and maximum absorbed chloride ion values calculated in Section 4.2 for each depth, ( 5 ) a statement detailing whether or not the surface abrasion described in Section 3.1 was performed.
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4.
Ts-3~ Copyright American Association of State Highway and Transportation Officials Provided by IHS under license with AASHTO No reproduction or networking permitted without license from IHS
T 259-3 Not for Resale
AASHTO
